Portable type fastener driving devices of the type herein contemplated are the type that include a portable frame structure having nosepiece structure defining a fastener drive track, a fastener driving element slidably mounted in the drive track, a magazine assembly for feeding a supply of fasteners along a feed track so as to move a leading fastener into the drive track and a manually actuated fastener driving system for moving the fastener driving element through successive cycles each of which includes a drive stroke and a return stroke.
The invention is particularly directed to devices of the type described which include a spring biased latch assembly, such as disclosed in U.S. Pat. No. 5,297,713, operable to allow the magazine assembly containing a rearward portion of the fastener guiding section of the drive track to yieldingly move rearwardly or to be moved rearwardly into a fastener jam clearing position. While the spring biased latch assembly has worked effectively in operation, there is always a need to provide a more cost effective latch assembly and has the following four operational features: (1) provides easy access to the drive track enabling the user to clear a jammed fastener quickly; (2) enables the user to unlatch the magazine assembly using one hand while holding the device with the other hand; (3) allows the user to clear a jam without tools; and (4) prevents self unlatching of the magazine assembly.